Electrolytic mist generator and washing machine using it

ABSTRACT

An electrolytic mist generating device includes electrode parts arranged inside an electrolytic cell, a piezoelectric element that generates mist of electrolytic water, a water supply device that supplies water into the electrolytic cell, a discharging device that discharges the mist generated in the electrolytic cell from an outlet, and a control circuit that controls steps, wherein in an electrolysis step, a voltage that does not permit the mist to be generated is applied to the piezoelectric element to generate a water column.

TECHNICAL FIELD

The present invention relates to an electrolytic mist generating devicefor disinfecting and antibacterial effects, and a washing machine usingthe same.

BACKGROUND ART

In recent years, technology for subjecting laundry to antibacterialtreatment during washing has been proposed. For example, PatentLiterature 1 discloses an electric washing machine with an ion generatorthat generates a metal ion having bacteriocidal capacity. PatentLiterature 2 discloses a washing machine with an Ag ion adding unit thatadds an Ag ion to cleaning water. Patent Document 3 discloses a washingmachine that water with an Ag ion eluted is sprayed onto clothing in ashower-like manner. Patent Literature 4 discloses a drier that squirts,on laundry, mist of water with an Ag ion eluted.

Typically, the elution of a metal ion is performed by electrolysis.Applying a voltage between electrodes for electrolysis allows the metalion to be eluted from the anodic electrode in accordance with Faraday'slaw.

However, in Patent Literatures 1 and 2, the water with the metal ioneluted is used in rinsing, and thus, the metal ion not attached to theclothing is discarded as drainage. Most of the metal ion thus goes towaste. Moreover, in Patent Literatures 3 and 4, the elution of the Agion is performed by a flow method using a flow path from water service,and thus, only electrolytic water of low-concentrated Ag ion is created.Therefore, a great amount of electrolytic water is needed for obtainingthe Ag ion that brings about the antibacterial effect to the washedclothing. In this case, since a piezoelectric element cannot generate somuch mist per unit time, processing time becomes very long.

[Patent Literature 1] Unexamined Japanese Utility Model Publication No.H05-74487

[Patent Literature 2] Unexamined Japanese Patent Publication No.2001-276484

[Patent Literature 3] Unexamined Japanese Patent Publication No.2005-87712

[Patent Literature 4] Unexamined Japanese Patent Publication No.2006-141579

DISCLOSURE OF THE INVENTION

One aspect of the present invention is to provide an electrolytic mistgenerating device including an electrolytic cell, electrode parts wherea pair of positive pole and negative pole are arranged in parallel andopposed to one another in the electrolytic cell, a piezoelectric elementthat generates mist of electrolytic water generated inside theelectrolytic cell, a water supply device that supplies water into theelectrolytic cell, a discharging device that discharges the mist fromthe electrolytic cell, and a control circuit that controls operationsteps of the electrolytic cell, wherein in an electrolysis step, avoltage that does not permit the mist to be generated is applied to thepiezoelectric element to generate a water column. Since in theelectrolysis step, by applying to the piezoelectric element the voltagethat does not permit the mist to be generated to generate the watercolumn, the electrolysis in the electrode parts is performed by a batchmethod, desired high-concentration metal ion water can be stably andcontinuously obtained in accordance with an electrolytic current valueand an electrolysis time. By applying to the piezoelectric element thevoltage that does not permit the mist to be generated to generate thewater column, aqueous solution during the electrolysis step can beefficiently circulated, so that a harmful effect such as nonuniformityof the solution accompanying the batch method and the like can beprevented. The piezoelectric element can have both the mist generationfunction and the water circulating function in the electrolytic cell.

Preferably, the control circuit executes a drainage step of dischargingelectrolytic water in the electrolytic cell. With this configuration,discharging the aqueous solution with a metal ion eluted by electrolysisafter the mist supply can prevent the aqueous solution remaining untilnext use from changing in quality, and settling out and accumulating todo harm to the device.

Preferably, the control circuit executes a water supply step ofsupplying water into the electrolytic cell after the drainage step. Withthis configuration, since a series of steps associated with theelectrolytic mist generation end in a state where the water is supplied,all the times, the inside of the electrolytic cell is not dry, and canbe maintained in a state where solid materials hardly occur.

Preferably, the control circuit executes a cleaning step of cleaning aninside of the electrolytic cell after the drainage step. By adding thecleaning step, the electrode parts and the inside of the electrolyticcell can be cleaned, and deposits and the like inside the electrolyticcell can be restrained for a long time, so that a stable state for theelectrolysis can be maintained.

Preferably, the control circuit executes a water supply step ofsupplying water into the electrolytic cell after the cleaning step. Withthis configuration, since the series of steps associated with theelectrolytic mist generation end in the state where the water issupplied, all the times, the inside of the electrolytic cell is not dry,and can be maintained in the state where solid materials hardly occur.

Preferably, the voltage that does not permit the mist to be generatedand is applied to the piezoelectric element may be ⅓ or more and ½ orless of a rated voltage that permits the mist to be generated. With thisconfiguration, although the water column generated from thepiezoelectric element extends above a water surface, it falls in a statewhere the mist generation by water crushing is not reached. As a result,a circulating water path from the piezoelectric element toward a watercolumn falling direction can be formed, so that the electrolytic statecan be made uniform from the electrode parts to the whole aqueoussolution inside the electrolytic cell.

Preferably, the water column generated from the piezoelectric elementmay be formed by a water flow passing though the electrode parts. Withthis configuration, the water circulation in the electrolysis step canbe smoothly performed, and harmful effects such as nonuniformity of thesolution accompanying the batch method can be prevented.

Preferably, the electrolytic cell may have a recessed part having apredetermined depth in a bottom portion thereof, and the piezoelectricelement may be arranged in the recessed part so as to be inclined. Withthis configuration, a volume of stored water at a level required forprotecting the piezoelectric element can be made as small as possible,and a volume of the aqueous solution with the metal ion eluted that isinvoluntarily wasted as drainage after the mist processing step can bereduced.

Preferably, the electrolysis step may be controlled by a constantcurrent circuit. With this configuration, even if properties of theservice water change to some extent, the electrolytic aqueous solutioncontaining a certain amount of Ag can be obtained, and uniform effectsto the clothing can be brought about.

Another aspect of the present invention is to provide a washing machineincluding the above-described electrolytic mist generating device, awashing tub that contains laundry, an outer tub in which the washing tubis internally mounted rotatably, and a water supply device that supplieswashing water to the outer tub, wherein mist of electrolytic watergenerated by the electrolytic mist generating device is supplied to thewashing tub. This can bring about disinfecting and antibacterial actionsto the clothing, and a mildewproofing action to the washing tub as well.By setting an attachment position of the electrolytic mist generatingdevice to a front-surface-side upper portion of horizontal or obliquetype washing tub, a user can also observe contact of the generated misthaving an average particle diameter of 10 μm with the washed clothinginside the washing tub, so that the user can visually check the clothingprocessing step with the mist to obtain a visual effect of the mistprocessing.

Preferably, an inner surface of an introduction part from theelectrolytic mist generating device to the washing tub may be subjectedto water repellent treatment. This allows the generated mist to reachthe washed clothing while restraining, as much as possible, loss of themist due to attachment to a wall surface until it is introduced to thewashing tub.

Preferably, the electrolytic mist generating device may supply mist ofAg ion electrolytic water of 20 ppm or more and 200 ppm or less to thewashing machine. With this configuration, the high-concentrationelectrolytic ion aqueous solution can reduce a liquid volume requiredfor the clothing, resulting in a reduction in mist processing time.

Preferably, the supply of the mist to the washing tub may be performedwhile laundry is tumbled after a final spin drying step. With thisconfiguration, since after the high-concentration electrolytic ionaqueous solution is attached to the washed clothing, it further wets andspreads by utilizing the water contained in the clothing, unevenness inthe mist attachment could be corrected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration view of an electrolytic mist generating deviceof Embodiment 1.

FIG. 2 is a cross-sectional view of FIG. 1.

FIG. 3 is a top view showing an arrangement of electrode parts and apiezoelectric element inside an electrolytic cell.

FIG. 4 is a cross-sectional view of a washing and drying machinemounting the electrolytic mist generating device.

FIG. 5 is a back view of FIG. 4.

FIG. 6 is a system flowchart of the electrolytic mist generating deviceof Embodiment 1.

FIG. 7 is a configuration view of an electrolytic mist generating deviceof Embodiment 2.

FIG. 8 is a system flowchart of an electrolytic mist generating deviceof Embodiment 3.

FIG. 9 is a system flowchart of an electrolytic mist generating deviceof Embodiment 4.

DESCRIPTION OF REFERENCE MARKS

1 electrolytic cell

2 electrode part

4 piezoelectric element

5 recessed part

6 rectifier

7 blowing fan

8 mist outlet

9 water supply and drain port

10 body

12 cylindrical outer tub

13 clothing

14 cylindrical inner tub

15 drive motor

40 electrolytic mist generating device

41 mist introducing path

50 water supply device

70 discharging device

80 control circuit

PREFERRED EMBODIMENTS FOR CARRYING OUT OF THE INVENTION

Hereinafter, embodiments of the present invention are described withreference to the drawings. These embodiments, however, do not limit thepresent invention.

Embodiment 1

FIG. 1 is a schematic configuration view of an electrolytic mistgenerating device according to Embodiment 1 of the present invention,FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a top view ofelectrode parts and a piezoelectric element.

Two sheets of electrode parts 2 are arranged in parallel with respect toa bottom surface of electrolytic cell 1. Electrode parts 2 arespecifically Ag plates of 2 cm×5 cm having a thickness of 1.2 mm, andspaced from each other at a distance of 8 mm. Terminal part 2 a forapplying a voltage through rubber packing 3 from each of electrode parts2 is drawn outside electrolytic cell 1. Each of electrode parts 2 isfixed to the bottom surface of electrolytic cell 1 by rubber packing 3.

Piezoelectric element 4 is arranged adjacent to a position where agenerated water column is formed by a water flow passing between twosheets of electrode parts 2. In a bottom portion, there is providedrecessed part 5 having a predetermined depth of 15 mm from the bottomsurface of electrolytic cell 1, where piezoelectric element 4 isdisposed so as to keep an inclination of about 10 degrees. As a result,the water column generated from piezoelectric element 4 is formed withan angle in an oblique direction and is formed by the water flow passingbetween electrode parts 2 spaced from each other at a distance of 8 mm,so that a circulating water path from piezoelectric element 4 toward awater column falling direction can be formed. Specifically,piezoelectric element 4 of φ20 mm and 1.6 MHz for rated AC 48V is used.

Moreover, above electrode parts 2, rectifier 6 having a substantiallysemi-cylindrical shape is disposed in a portion at a certain distancefrom a top surface position of electrolytic cell 1 so as to be fixed toa top surface portion. Specifically, it has a semi-cylindrical shape ofφ35 mm×60 mm and is made of glass having thickness of 1 mm. Rectifier 6is laid out so that during the mist supply, the water column generatedfrom piezoelectric element 4 crashes against rectifier 6 having thesubstantially semi-cylindrical shape while performing water crushing,and that the water then falls between two sheets of electrode parts 2 tobe returned.

On the top surface of electrolytic cell 1 about 10 mm above rectifier 6having the substantially semi-cylindrical shape, there is disposedblowing fan 7 as discharging device 70 that discharges mist generatedinside electrolytic cell 1. Blowing fan 7 is made of an axial flow fanhaving a diameter of 30 mm. A configuration is made such that wind fromblowing fan 7 is blocked off by rectifier 6 having the substantiallysemi-cylindrical shape, passes through clearances of about 5 mm betweenan inner wall surface of electrolytic cell 1 and rectifier 6, and flowsin an inside direction, so that the wind is supplied to the water columngenerated from the piezoelectric element 4 from a side surfacedirection. In a side-surface upper portion of electrolytic cell 1, thereis disposed mist outlet 8.

Moreover, in recessed part 5 of electrolytic cell 1 where piezoelectricelement 4 is disposed, water supply and drain port 9 is provided.Switching valve 60 connects water supply and drain port 9 to watersupply device 50 during water supply and to drain pipe 61 duringdrainage. Water service pipe 51 is connected to water supply device 50.Control circuit 80 arranged in the vicinity of electrolytic cell 1controls operation steps of electrolytic cell 1 through coupling notshown. A water level sensor (not shown) is provided in electrolytic cell1 to perform water-supply upper-limit level management to electrolyticcell 1, and lower-limit level management when the mist is generated.

FIG. 4 is a cross-sectional view of a washing and drying machine withthe electrolytic mist generating device of Embodiment 1 of the presentinvention installed, and FIG. 5 is a back view of FIG. 4.

Cylindrical outer tub 12 supported elastically by a plurality ofsuspensions 11 is provided inside body 10, and vibrations during washingand spin drying are absorbed by suspensions 11. Inside outer tub 12,cylindrical inner tub 14 to contain clothing 13 is rotatably provided,and is rotatively driven by drive motor 15 as a drive device. Outer tub12 serves as a washing chamber of clothing 13 in a washing step andserves as a drying chamber of clothing 13 in a drying step.

Opening part 10 a for taking clothing 13 in and out, and door 16 foropening and closing the same are provided in a front surface of body 10.Door 16 is made of transparent glass so that the clothing inside thewashing tub can be observed. Outer tub 12 and inner tub 14 also havesimilar opening parts on the front surface side thereof, and thisopening part of outer tub 12 is watertightly joined to opening part 10 aof body 10 by a bellows. In a bottom portion of outer tub 12, drain port17 for discharging washing water is provided, and is joined to drainvalve 18 that opens and closes a drain path. Drain valve 18 is closedduring washing so that a predetermined volume of washing water can bestored in outer tub 12. Blower 19 as a blowing device is provided in anupper portion of body 10.

Blower 19 suctions drying air, which has passed through inner tub 14 andouter tub 12, from outer tub outlet 20 provided above outer tub 12, andblow an inside of upstream circulating air path 21 provided in a backsurface of outer tub 12 to derive the air from upstream circulatingair-path inlet 22 to upstream circulating air-path outlet 23 asindicated by arrow a. Moreover, downstream circulating air path 24 isprovided in an outer surface of outer tub 12, and the drying air comingin through downstream circulating air-path inlet 25 is blown in adirection of arrow b to be supplied into outer tub 12 and inner tub 14through blowing port 26.

In a back-surface lower portion of outer tub 12 is arranged heat pumpdevice 30 in which compressor 27, radiator 28 that radiates heat of acompressed refrigerant, a pressure reducing device (not shown) forreducing a pressure of the high-pressure refrigerant, and heat absorber29 in which the low-pressure refrigerant resulting from the reduction ofpressure removes heat from a vicinity are joined to one another by pipeline so as to circulate the refrigerant through them, and an empty spaceinside body 10 is effectively utilized to house heat pump device 30.Heat-exchanging air path 31 serves to cause the air blown by blower 19to flow from heat absorber 29 to heat radiator 28 in a direction ofarrow c, and contains compressor 27 alongside of heat absorber 29 andheat radiator 28 in a lateral direction of body 10 insideheat-exchanging air path 31. An inlet side of heat-exchanging air path31 is communicated with upstream circulating air-path outlet 23, and anoutlet side thereof is communicated with downstream circulating air-pathinlet 25.

In upstream circulating air path 21 from outer tub 12 to heat absorber29, exhaust port 32 for exhausting the air flowing here outside body 10is provided in an upper surface of body 10. Freely opened and closedlouver 33 is provided in exhaust port 32 so as to enable selection as towhether or not to perform the exhaust from exhaust port 32 andadjustment of an exhaust direction.

Moreover, intake port 34 for taking in external air is provideddownstream of exhaust port 32 in upstream circulating air path 21.Intake port 34 is located between exhaust port 32 and blower 19, and anopening and closing device of intake port 34 is made of intake valve 35consisting of an opening and closing valve such as an electromagneticvalve so as to enable selection as to whether or not to perform theintake.

Downstream circulating air-path inlet 25 and heat-exchanging air-pathoutlet 31 a are communicated through air supply hose 36 made of aflexible material, which is capable of extension and contraction in abellows-like manner, and outer tub outlet 20 and upstream circulatingair-path inlet 22 are communicated through exhaust hose 37 made of aflexible material, which is capable of extension and contraction in abellows-like manner, which prevents the vibrations of outer tub 12 frombeing transmitted to heat pump device 30. Moreover, in a lower portionof heat-exchanging air path 31, drain water vessel 38 for collectingdehumidified water from heat absorber 29 is provided, and the watercollected in drain water vessel 38 is discharged outside the machinefrom drain pump 39.

In heat pump device 30, compressor 27, radiator 28 that radiates heat ofthe compressed refrigerant, the pressure reducing device for reducingthe pressure of the high-pressure refrigerant and made of a throttlevalve, a capillary and the like, and heat absorber 29 in which thelow-pressure refrigerant resulting from the reduction of pressureremoves heat from the vicinity are joined to one another by pipe line soas to circulate the refrigerant through them, so that a heat pump cycleis realized.

Electrolytic mist generating device 40 is arranged in a front upperportion of body 10. Mist introducing path 41 joins electrolytic mistgenerating device 40 and outer tub 12 to lead generated mist to innertub 14, thereby enabling mist processing for clothing 13. Mistintroducing path 41 is subjected to water repellent treatment in orderto restrain mist attachment to a path wall surface as much as possible.Specifically, fluorine resin coating is applied to the same.

Next, operation of the electrolytic mist generating device is described.FIG. 6 is a system flowchart showing the operation of the electrolyticmist generating device.

First, a water supply step of supplying service water into electrolyticcell 1 up to a predetermined water level is performed. Water supplydevice 50 supplies water into electrolytic cell 1 through switchingvalve 60 and water supply and drain port 9 and stops the water supplywhen the predetermined water level is sensed by the water level sensor.For example, service water of about 100 ml having a hardness of about 40and an electric conductivity of 150 μS/cm is supplied, so that the waterlevel in electrolytic cell 1 becomes 30 mm from the bottom surface.

Thereafter, as an electrolysis step, AC 24 V is applied to piezoelectricelement 4 as a voltage that does not permit the mist to be generated,thereby enabling the water inside electrolytic cell 1 to circulatetherethrough. Almost concurrently, a voltage is applied utilizing aconstant current circuit so as to pass DC 30 mA through electrode parts2. The water column generated from piezoelectric element 4 is formed bya water flow passing between electrode parts 2, and returning waterafter forming the water column in an oblique upper direction also fallsbetween electrode parts 2, thereby increasing an effect of putting theelectrolytic water into a uniform state. Electrolysis is performed for atotal of 200 seconds while a polarity of the electrodes to which thevoltage is applied is inverted every about 20 seconds. At this time,about 15 V is applied as a DC voltage. As a result, an aqueous solutionof about 50 ppm containing an Ag ion and AgCl, which is cloudy to someextent, is obtained.

Thereafter, as a mist supply step, AC 48 V is applied to piezoelectricelement 4 to produce a state capable of generating the mist. At the sametime, blowing fan 7 and drive motor 15 are also activated. Although thewater column generated from piezoelectric element 4 crashes againstrectifier 6 while performing water crushing, it does not lose retainedenergy after crashing against rectifier 6, and then, water detachment iscreated by blowing fan 7. As a result, the mist generated bypiezoelectric element 4 is discharged from mist outlet 8 by blowing fan7 and arrives at washed clothing 13 in inner tub 14 through mistintroducing path 41.

Wind of about 50 L/min. is introduced into inner tub 14 by blowing fan7. At this time, clothing 13 weighs about 4 kg based on dry weight, andweighs about 5.6 kg in a state where water is contained. Theelectrolytic mist can be generated at a level of about 12 ml/min bypiezoelectric element 4, and variation in volume of generated mist iscaused to some extent depending on the water level. The mist supply stepcontinues until the water level sensor senses the predetermined waterlevel, and when it is sensed, piezoelectric element 4 and blowing fan 7stop. For example, by sensing timing when the water level reachesrecessed part 5 from the bottom surface of electrolytic cell 1, a volumeof the electrolytic ion water to be subsequently discharged can bereduced.

The mist will be attached to entire clothing 13 by drive motor 15 forabout 10 minutes while clothing 13 is tumbled inside inner tub 14. An Agconcentration of the electrolytic ion water is high to some extent, andalso, the water contained in the clothing allows the electrolytic ionwater after the attachment to the clothing to wet and spread to aportion to which the mist is not attached, and thus, tumbling for about10 minutes puts the entire clothing of 4 kg into a state where theelectrolytic ion water is almost uniformly attached thereto.

The mist generated by the piezoelectric element is made of very smallparticles having an average particle diameter of 10 μm, which is in awhite smoke-like state. A user can thus observe the mist processing stepthrough the door of the washing and drying machine. Moreover, since themist intrudes between inner tub 14 and outer tub 12 to be attached tosome extent, periodically utilizing the mist processing functioneffectively brings about disinfecting and antibacterial effects on innertub 14 and outer tub 12, and utilizing the electrolytic mist generatingdevice allows the washing tub to be continuously maintained in a statefree of mold.

Moreover, as an improved additional value of the heat pump type washingmachine, even in a case where dehumidification for a room where thewashing machine is installed is performed, since the mist processingfunction maintains the disinfecting and mold-free state inside thewashing machine, nasty smell is restrained from being caused even whenthe washing machine inside is utilized as a blower circuit.

Thereafter, as a drainage step, the electrolytic ion water remaining inrecessed part 5 is discharged from drain pipe 61 through water supplyand drain port 9 and switching valve 60 to end a series of operation.

Since the mist supply step to clothing 13 is performed after spin dryingoperation of the washing and drying machine, the water supply step andthe electrolysis step are performed prior to the mist supply step.

Evaluations of the antibacterial effect were made for the clothingsubjected to the mist processing. For the evaluations, a quantitativetesting method based on JIS L1902 was referred to. The evaluations weremade by sewing desized testing fabrics on clothing of 4 kg with threadin ten positions. As a result, in all the fabrics, a bacteriostaticactivity value of 2 or more could be obtained.

Embodiment 2

In the present embodiment, an electrolytic mist generating deviceresembles that of the first embodiment, and thus, a detailed descriptionof the entire device is omitted. FIG. 7 is a schematic configurationview of the electrolytic mist generating device in a second embodimentof the present invention.

In discharging device 70, a blowing fan is not provided, but intake port42 is provided. A configuration is adapted such that the inside ofelectrolytic cell 1 is put into a negative pressure state to take in airfrom intake port 42 and that the generated mist is discharged outside ofelectrolytic cell 1. When a description is given to the washing machineshown in FIG. 4, by operating blower 19, a negative pressure force actson the mist outlet 8 side of electrolytic mist generating device 40 sothat the mist generated inside electrolytic cell 1 is directed to theinner tub 14 side.

Embodiment 3

Also, in the present embodiment, an electrolytic mist generating deviceresembles that of the first embodiment, and thus, a detailed descriptionof the entire device is omitted. As a different point from the firstembodiment, operation of the electrolytic mist generating device isdescribed. FIG. 8 is a system flowchart showing the operation of theelectrolytic mist generating device.

Here, after the drainage step, a cleaning step is added. Specifically,after the drainage step, service water is supplied from water supply anddrain port 9 up to a predetermined water level. Once the predeterminedwater level is sensed by the water level sensor, the switching valve isturned to a drainage direction to discharge the stored water at a time.This allows electrode part 2 surfaces used in the electrolysis, anelectrolytic cell 1 inner surface or a piezoelectric element 4 surfaceto be cleaned in each use. Accordingly, even when a use interval of theelectrolytic mist generating device becomes long, deposit accumulationcan be restrained in long-term use because the inside of theelectrolytic mist generating device has been cleaned. Even if thedeposit accumulation occurs, the cleaning step allows the deposits to bedischarged outside.

Embodiment 4

Also, in the present embodiment, an electrolytic mist generating deviceresembles that of the first embodiment, and thus, a detailed descriptionof the entire device is omitted. As a different point from the firstembodiment, operation of the electrolytic mist generating device isdescribed. FIG. 9 is a system flowchart showing the operation of theelectrolytic mist generating device.

Here, after the series of electrolytic mist generating operation ends,electrolytic cell 1 is put into a state where water is stored to preparefor the next use. Accordingly, as a first step, the processing startswith a water replenishing step of replenishing shortage in volume ofwater with respect to the predetermined water level. Thereafter, theoperation proceeds as in the second embodiment, and after the cleaningstep, a water supply step is added. This will allow the electrode part 2surfaces used in the electrolysis, the electrolytic cell 1 inner surfaceor the surface of piezoelectric element 4 to be cleaned in each use.

Finally, since electrolytic cell 1 is put into the state where the wateris stored to prepare for the next use, the inside of the electrolyticmist generating device is not dry even if the use interval of theelectrolytic mist generating device becomes long. Thereby, the devicecan be maintained in a state where solid materials hardly occur even ina long-term use. Even if deposits occur, they can be discharged outsidein the cleaning step.

While in the present embodiment, the water supply step is performedafter the cleaning step, in a system flow in which the water supply stepis added after the drainage step, similarly, the inside of theelectrolytic mist generating device is not dry even if the use intervalof the electrolytic mist generating device becomes long, and thus, thedevice can be maintained in a state where solid materials hardly occureven in a long-term use.

While in the embodiments of the present invention, the piezoelectricelement of 1.6 MHz is used, one that can be used in the presentinvention is not limited to this, 1.6 MHz is common in a piezoelectricelement for use in a humidifier or the like, and produces a mistparticle diameter of an average of about 4 μm. In addition to this, 2.4MHz or 1 MHz is usable. However, with 2.4 MHz, a range of the waterlevel enabling the mist to be generated is smaller as compared with 1.6MHz. Moreover, with 1 MHz, a water level required for protecting thepiezoelectric element from being destroyed due to idling becomes higher,and thus, the depth of the recessed part needs to larger.

While in the present embodiments of the present invention, thepiezoelectric element is arranged by providing the recessed part havingthe depth of 15 mm from the bottom surface of the electrolytic mistgenerating cell, the arrangement that can be used in the presentinvention is not limited to this. A point to notice in the mistgeneration from the piezoelectric element is that an upper surface ofthe piezoelectric element should not be in a boil-dry state inoperation. Accordingly, a certain lower-surface water level enabling theusage is required, and as a result, the electrolytic water remains eachtime the electrolytic mist generating device is used. It is desirable todiscard the remaining electrolytic water instead of leaving it as it is.Thus, providing the recessed part in the piezoelectric element part ofthe electrolytic mist generating cell can reduce a discarded volume ofelectrolytic water as much as possible. Moreover, by optimizing thedepth of the recessed part in a range of 10 mm or more and 30 mm orless, the mist generation is enabled down to a border line between thebottom surface of the electrolytic mist generating cell and the recessedpart.

While in the embodiments of the present invention, the piezoelectricelement holds the inclination of 10 degrees with respect to theelectrolytic cell bottom surface, the inclination that can be used inthe present invention is not limited to this. It is considered to bedesirable that the piezoelectric element has an inclination of at least5 degrees or more inclination for effectively detaching the mist fromthe water column generated from the piezoelectric element. Moreover,although it is preferable that the inclination is larger to some extentfor directing the circulating water in a electrode part directionadjacent to the piezoelectric element, too large an inclination reducesan effective water-level range enabling the mist generation, and thus,it is considered to be desirable that the inclination is set up to about30 degrees.

While in the embodiments of the present invention, in the mist supplystep, the predetermined lower surface water level is set to the borderwith respect to the recessed part provided in the electrolytic cellbottom surface, it is not limited to this. After the mist generation,however, discarding the remaining electrolytic water instead of leavingthe same until the next use advantageously causes no trouble.Accordingly, setting the water level to the bottom surface of theelectrolytic cell or lower is desirable because of less wasteful waterwith the metal ion eluted.

While in the embodiments of the present invention, the substantiallysemi-cylindrical rectifier made of glass is used, one that can be usedin the present invention is not limited to this. Any material that doesnot so largely attenuate energy that the water column possesses may beemployed. A resin material is not preferable because it considerablyabsorbs and attenuates the energy that the water column possesses. Inaddition to glass, aluminum, stainless steel, ceramics and the like canbe used.

While in the embodiments of the present invention, as the voltage thatdoes not permit the piezoelectric element to generate the mist, ½ of therated voltage for use in mist generation is employed, the voltage is notlimited to this. Once the voltage exceeds ½, a volume of generated mistgradually becomes larger, which, in some cases, gives rise to a need forregulation to inhibit the generated mist from flowing outside. Less than3/1 does not produce the water column from the water surface, resultingin a remarkable deterioration in a circulating state of the water.Accordingly, with the voltage that does not permit the mist to begenerated, a range of ⅓ or more and ½ or less of the rated voltage ispreferable.

While in the embodiments of the present invention, the electrolysis stepis controlled by the constant current circuit, the step is not limitedto this. As in Japan, in a case where the service water is soft waterand characteristics thereof is constant to some extent, the constantcurrent circuit can make effects by the Ag processing more uniform,while when the hardness of water is higher as is often a case in othercountries, electrolysis at a constant voltage can make the effects bythe Ag processing more uniform.

While in the embodiments of the present invention, the electrolytic mistgenerating device is disposed in the front-surface-side upper portion ofthe oblique washing tub, the position is not limited to this. However,since disposing the electrolytic mist generating device in thefront-surface-side upper portion allows the user to observe contact ofthe mist having an average particle diameter of 10 μm or less withwashed clothing inside the washing tub, the user can visually check theclothing processing step with the mist.

While in the embodiments of the present invention, as the electrolysisstep, the Ag ion water of 50 ppm is used, the concentration is notlimited to this. Ag of 1 mg needs to be carried for clothing of 1 kg forstably obtaining the antibacterial effect in the clothing, and thus, Agof 4 mg or more is needed for standard clothing of 4 kg. Moreover, avolume of mist that can be generated by the piezoelectric element isabout 15 g/min. or less. Although dilute Ag ion water is preferable forevenly carrying Ag on the clothing, processing time becomes longer. Ifthe Ag ion water is concentrated excessively, it turns brownish fromcloudy, which causes a concern of the harmful effect on the clothing.Accordingly, in light of the volume of the generated mist, theprocessing time and the harmful effect on the clothing, as a AG ionconcentration, the usage at a level of 20 ppm or more and 200 ppm orless in 250 ml or less and 25 ml or more for the standard clothing of 4kg is considered to be preferable.

While in the embodiments of the present invention, the mist supply stepis performed while tumbling is performed after the final spin dryingstep, the step is not limited to this. However, after the electrolyticion aqueous solution is attached to the washed clothing, theelectrolytic ion aqueous solution further wets and spreads by utilizingcontained water in the clothing, and even if unevenness in the mistattachment occurs, it could be corrected. Thus, reduction in theprocessing time can be achieved by utilizing high-concentration Ag ionwater.

INDUSTRIAL APPLICABILITY

As described above, the electrolytic mist generating device of thepresent invention, which is a device capable of stably and continuouslyproducing high-concentration metal ion water, can be applied to a widerange of applications such as an air washer, an air conditioner orwater-related equipment requiring disinfection.

1. An electrolytic mist generating device comprising: an electrolyticcell; electrode parts where a pair of positive pole and negative poleare arranged in parallel and opposed to one another in the electrolyticcell; a piezoelectric element that generates mist of electrolytic watergenerated inside the electrolytic cell; a water supply device thatsupplies water into the electrolytic cell; a discharging device thatdischarges the mist from the electrolytic cell; and a control circuitthat controls steps, wherein in an electrolysis step, a voltage thatdoes not permit the mist to be generated is applied to the piezoelectricelement to generate a water column.
 2. The electrolytic mist generatingdevice according to claim 1, wherein the control circuit executes adrainage step of discharging electrolytic water in the electrolyticcell.
 3. The electrolytic mist generating device according to claim 2,wherein the control circuit executes a water supply step of supplyingwater into the electrolytic cell after the drainage step.
 4. Theelectrolytic mist generating device according to claim 2, wherein thecontrol circuit executes a cleaning step of cleaning an inside of theelectrolytic cell after the drainage step.
 5. The electrolytic mistgenerating device according to claim 4, wherein the control circuitexecutes a water supply step of supplying water into the electrolyticcell after the cleaning step.
 6. The electrolytic mist generating deviceaccording to claim 1, wherein the voltage that does not permit the mistto be generated and is applied to the piezoelectric element is ⅓ or moreand ½ or less of a rated voltage permitting the mist to be generated. 7.The electrolytic mist generating device according to claim 1, whereinthe water column generated from the piezoelectric element is formed by awater flow passing though the electrode parts.
 8. The electrolytic mistgenerating device according to claim 1, wherein the electrolytic cellhas a recessed part having a predetermined depth in a bottom portionthereof, and the piezoelectric element is arranged so as to be inclinedin the recessed part.
 9. The electrolytic mist generating deviceaccording to claim 1, wherein the electrolysis step is controlled by aconstant current circuit.
 10. A washing machine comprising: theelectrolytic mist generating device according to claim 1; a washing tubthat contains laundry; an outer tub in which the washing tub isinternally mounted rotatably; and a water supply device that supplieswashing water to the outer tub, wherein mist of electrolytic watergenerated by the electrolytic mist generating device is supplied to thewashing tub.
 11. The washing machine according to claim 10, wherein aninner surface of an introduction part from the electrolytic mistgenerating device to the washing tub is subjected to water repellenttreatment.
 12. The washing machine according to claim 10, wherein theelectrolytic mist generating device supplies mist of Ag ion electrolyticwater of 20 ppm or more and 200 ppm or less.
 13. The washing machineaccording to claim 10, wherein the supply of the mist to the washing tubis performed while laundry is tumbled after a final spin drying step.